BTMETER 866A Pro handheld HVAC anemometer CFM air flow meter — wet-bulb temp, USB data-logging, backlit display

The BTMETER 866A Pro is a handheld HVAC anemometer that measures wind speed, CFM air flow, temperature, relative humidity and dew point with USB data-logging for balancing ducts and field testing.

Compact yet feature-rich, the 866A Pro is designed for HVAC technicians, maintenance teams and anyone who needs precise airflow measurements on-site. It combines an 8-vane sensor, large backlit display and PC connectivity so you can verify vent performance, record readings and analyze results without manual conversions. The unit’s durable housing, tripod mount and protective case make it practical for both indoor and outdoor use.

How accurate and wide-ranging are the wind and airflow measurements?

The 866A Pro covers typical HVAC and environmental ranges with high resolution and repeatability. Wind velocity is measured from 0.3 to 40 m/s with ±2.0% + 50 (displaying in six units), while temperature and humidity sensors report air conditions used to derive dew point and wet-bulb values.

• Wind speed: 0.3–40 m/s, resolution down to 0.01 where applicable
• Units: m/s, km/h, ft/min, knots, mph, fpm
• Temperature: 14°F–140°F (±2.7°F), selectable ℃/℉
• Airflow volume: 0 to 999,900 ft3/min (CFM) shown directly

Can I log readings and analyze them on a computer?

Yes — the meter includes a USB cable and PC software to stream and store measurements for later review. This makes it easy to create reports, compare max/min values and keep time-stamped logs during balancing or troubleshooting sessions.

• Real-time USB connection to PC for monitoring and recording
• Software supports graphing, export and analysis of wind, temp, RH and CFM
• Max/Min capture helps document peak and low airflow during tests
• Tripod-mountable base for stable, hands-free logging

What features make it practical in the field?

The 866A Pro is built for portability and repeated field use: a protective case, large backlit screen and auto-shutoff help conserve battery life, while the sensitive 8-vane sensor detects slow flows typical in HVAC systems. Small form factor and a metal screw hole for tripod mounting speed up multi-point measurements.

• Protective carrying case included for transport and storage
• Large backlit LCD for low-light job sites and quick reads
• Auto power-off and low-battery indicator to extend battery life
• Tripod mount for hands-free, repeatable positioning

Tips for reliable temperature and humidity readings: the device’s temp/RH sensors sit behind the instrument’s side vents; shield these from direct sunlight and ensure air is flowing across the holes for accurate, responsive readings. With no airflow, temperature and humidity will change slowly — this behavior is expected and preserves measurement stability.

Who is this for? The BTMETER 866A Pro is aimed at HVAC contractors, building engineers, facility managers, home inspectors and hobbyists needing dependable airflow and environmental metrics. It’s well suited for duct balancing, vent testing, AC output checks, ventilation troubleshooting and any task where CFM, wind speed and ambient conditions must be recorded and verified. If you require portable, USB-capable logging plus clear, direct CFM readouts without manual conversion, this meter is a practical choice.